Freedom of speech is never absolute, but at what point do you think it reasonable and justified?
Its reasonable as long as others are allowed to criticize the speech of the other exercising their freedom.
Cult like JWS and Islam demand freedom of religion/speech, but prohibit from others.
Idiotic things like JW indoctrination cartoons and KKK hate demonstrations are allowed but the majority are allowed to tell them they are f--cking idiots. This freedom, and the freedom to criticize should keep things in check, once that is lost one extreme will take over.
Freedom of speech is only dangerous when it becomes one sided, when you are the good extremism as long as you are the right kind of extreme.
Freedom of speech HAS to be absolute to work. So a few crack pots can say whatever they want as long as they can be challenged not silenced.